Tutorial by Examples: o

Generator expressions are similar to list, dictionary and set comprehensions, but are enclosed with parentheses. The parentheses do not have to be present when they are used as the sole argument for a function call. expression = (x**2 for x in range(10)) This example generates the 10 first perfe...

The background-color property sets the background color of an element using a color value or through keywords, such as transparent, inherit or initial. transparent, specifies that the background color should be transparent. This is default. inherit, inherits this property from its parent e...

Jsoup can be be used to easily extract all links from a webpage. In this case, we can use Jsoup to extract only specific links we want, here, ones in a h3 header on a page. We can also get the text of the links. Document doc = Jsoup.connect("http://stackoverflow.com").userAgent("Mozi...

a, b = 1, 2 # Using the "+" operator: a + b # = 3 # Using the "in-place" "+=" operator to add and assign: a += b # a = 3 (equivalent to a = a + b) import operator # contains 2 argument arithmetic functions for the examp...

CSS transforms are based on the size of the elements so if you don't know how tall or wide your element is, you can position it absolutely 50% from the top and left of a relative container and translate it by 50% left and upwards to center it vertically and horizontally. Keep in mind that with this...

Create a new file called hello.sh with the following content and give it executable permissions with chmod +x hello.sh. Execute/Run via: ./hello.sh #!/usr/bin/env bash # Note that spaces cannot be used around the `=` assignment operator whom_variable="World" # Use printf to sa...

HTML: <div id="element-one">Hello I am some text.</div> <div id="element-two">Hello I am some smaller text.</div> CSS: #element-one { font-size: 30px; } #element-two { font-size: 10px; } The text inside #element-one will be 30px ...

a, b = 1, 2 # Using the "-" operator: b - a # = 1 import operator # contains 2 argument arithmetic functions operator.sub(b, a) # = 1 Possible combinations (builtin types): int and int (gives an int) int and float (gives a float) int and comp...

a, b = 2, 3 a * b # = 6 import operator operator.mul(a, b) # = 6 Possible combinations (builtin types): int and int (gives an int) int and float (gives a float) int and complex (gives a complex) float and float (gives a float) float and complex (gives a comple...

Python does integer division when both operands are integers. The behavior of Python's division operators have changed from Python 2.x and 3.x (see also Integer Division ). a, b, c, d, e = 3, 2, 2.0, -3, 10 Python 2.x2.7 In Python 2 the result of the ' / ' operator depends on the type of the nu...

a, b = 2, 3 (a ** b) # = 8 pow(a, b) # = 8 import math math.pow(a, b) # = 8.0 (always float; does not allow complex results) import operator operator.pow(a, b) # = 8 Another difference between the built-in pow and math.pow is that the built-in po...

By default, the math.log function calculates the logarithm of a number, base e. You can optionally specify a base as the second argument. import math import cmath math.log(5) # = 1.6094379124341003 # optional base argument. Default is math.e math.log(5, math.e) # = 1.6094379124341003 ...

Rounding Math.round() will round the value to the closest integer using half round up to break ties. var a = Math.round(2.3); // a is now 2 var b = Math.round(2.7); // b is now 3 var c = Math.round(2.5); // c is now 3 But var c = Math.round(-2.7); // c is now -3 va...

A practical use case of a generator is to iterate through values of an infinite series. Here's an example of finding the first ten terms of the Fibonacci Sequence. def fib(a=0, b=1): """Generator that yields Fibonacci numbers. `a` and `b` are the seed values""" ...

Direction-Specific Properties CSS allows you to specify a given side to apply margin to. The four properties provided for this purpose are: margin-left margin-right margin-top margin-bottom The following code would apply a margin of 30 pixels to the left side of the selected div. View Resu...

You can include another Git repository as a folder within your project, tracked by Git: $ git submodule add https://github.com/jquery/jquery.git You should add and commit the new .gitmodules file; this tells Git what submodules should be cloned when git submodule update is run.

When you clone a repository that uses submodules, you'll need to initialize and update them. $ git clone --recursive https://github.com/username/repo.git This will clone the referenced submodules and place them in the appropriate folders (including submodules within submodules). This is equivale...

Anchors can be used to jump to specific tags on an HTML page. The <a> tag can point to any element that has an id attribute. To learn more about IDs, visit the documentation about Classes and IDs. Anchors are mostly used to jump to a subsection of a page and are used in conjunction with header...

Python provides string interpolation and formatting functionality through the str.format function, introduced in version 2.6 and f-strings introduced in version 3.6. Given the following variables: i = 10 f = 1.5 s = "foo" l = ['a', 1, 2] d = {'a': 1, 2: 'foo'} The following statem...

One method is available for counting the number of occurrences of a sub-string in another string, str.count. str.count(sub[, start[, end]]) str.count returns an int indicating the number of non-overlapping occurrences of the sub-string sub in another string. The optional arguments start and end ...